As generally discussed in U.S. Pat. No. 4,316,417 to Martin, railway car tracks generally include two windowed side frames and a truck bolster having ends disposed in the windows for permissible vertical and horizontal movement therein. The bolster extends across the truck and is supported by load carrying springs between the side frames and the bolster ends. Pockets are usually provided in the side frames or the bolsters to receive wedge or friction shoes. Each shoe has a vertical friction surface which engages a friction surface on the vertical column of the side frame and an inclined wedging friction surface engaging an inclined friction surface on the bolster. There may be one or two such wedge and pocket assemblies at each end of the bolster. Wear resistant wear plates are provided on the vertical columns of the side frame coming into engagement with the friction wedge. Many known techniques have been utilized to secure the wear plate to the column.
One such technique was to use a body side bearing bolt and a flange locknut sold under the trademark CAMRAIL® and which are manufactured and sold by licensees and/or related companies of the assignee of the present application, namely Acument Intellectual Properties, LLC. The description of the structure of the CAMRAIL® bolts and locknuts, as well as their installations, are illustrated in FIGS. 3 and 4.
The CAMRAIL® bolt 20 is best illustrated in FIG. 1. The bolt 20 has an enlarged head 22 defining top and bottom surfaces 24, 26 thereof. The top surface 24 is flat and the bottom surface 26 tapers from the top surface 24 to a stem 28 of the bolt 20, which extends outwardly to an end 30 of the bolt 20. The stem 28 is threaded from the end 30 to a position proximate to the tapered bottom surface 26 of the enlarged head 22, but not all the way to the tapered bottom surface 26. If desired, in other versions of the CAMRAIL® bolt (depending on the application to be used and the configuration of the side frames and wear plates), the bottom surface 26 may also be flat and separated from the top surface 24 such that the bottom surface 26 acts as a shoulder between the stem 28 and the enlarged head 22.
An extension member 32 extends outwardly from the top surface 24 of the enlarged head 22 of the bolt 20 to an opposite end 34 of the bolt 20. The extension member 32 has first and second portions 36, 38. The first portion 36 extends outwardly from the top surface 24 to the second portion 38. The second portion 38 extends outwardly from the first portion 36 to the end 34. The second portion 38 has an external TORX® drive configuration formed therein/thereon in order to allow the bolt 20 to be engaged at the second portion 38 of the extension member 32 in order to impart a driving or releasing torque to the bolt 20. Other versions of the CAMRAIL® bolt may have alternative drive configurations formed in/on the second portion 38 of the extension member, such as, for example, an external TORX PLUS® drive configuration. The second portion 38 has a larger outer diameter than the first portion 36 such that a groove 40 is formed between the second portion 38 of the extension member 32 and the top surface 24 of the enlarged head 22.
The locknut 42 is best illustrated in FIG. 2. The locknut 42 has an aperture 44 provided therethrough defining an aperture wall 46 which is threaded. An outer surface 48 of the locknut 42 has a plurality of flat surfaces, such as in a hex configuration, in order to allow for a tool, such as a wrench to engage the locknut 42 in order to tighten or loosen the locknut 42.
In application, as illustrated in FIGS. 3 and 4, the bolt 20 is inserted through a hole in the wear plate 70 and then through a hole in the side frame 80 until the enlarged head 22 of the bolt 20 is prevented from moving further through the holes. The hole in the wear plate 70 has a countersink in order to accommodate the tapered enlarged head 22 of the bolt 20. The non threaded portion of the stem 28 is positioned within the hole of the side frame 80. The locknut 42 is then secured to the stem 28 of the bolt 20 by threading the aperture wail 46 of the locknut 42 onto the threaded stem 28 until the locknut 42 bottoms out against the side frame 80. The locknut 42 is then engaged by a wrench on its outer surface 48 in order to hold the locknut 42 in place, i.e., to prevent further rotation of the locknut 42.
Thereafter, a torque applying tool is engaged with the external TORX® drive configuration on/in the second portion 38 of the extension member 32 of the bolt 20 in order to further tighten and secure the assembly of the bolt 20, locknut 42, wear plate 70 and side frame 80 together. In order to ensure that the assembly is not tightened too much, the extension member 32 is configured to break in the first portion 36 thereof when a predetermined torque is reached, as illustrated in FIG. 4.
Thereafter, it is necessary to ensure that the assembly is properly secured together, which is done by applying a predetermined amount of torque to the locknut 42, typically by a torque wrench. If the locknut 42 rotates in response to the application of this predetermined amount of torque applied by the torque wrench, the securement of the assembly is deemed to have failed, even if the bolt 20 had, in fact, had the proper clamp load applied to it. In this event, as the external TORX® drive configuration on/in the second portion 38 of the extension member 32 has already been broken off of the bolt 20, there is no way to reuse this bolt 20 in order to have it properly secure the assembly together. As such, the bolt 20 must be removed, typically by cutting or drilling, and a new bolt 20 must be used to secure the assembly together. Obviously, the failure of the bolt 20 causes increased time and expense as it requires the bolt 20 to be removed and the installation of a new bolt 20, which may or may not fail, such that if there is a failure, the process must again be repeated.
Thus, there is a need to have the ability to ensure that the bolt has the proper clamp load in order to properly secures the assembly together. It is also desirable to have a visual indicator that the nut has been subjected to the desired torque during initial assembly and application of nut torque. Furthermore, it is also desirable to be able to visually determine that the nut has been subjected to the desired torque during routine maintenance service that takes places at some point in time after the initial assembly. It would also be desirable to eliminate the initial cost, maintenance and calibration of a torque wrench.